Legendary Resistance (3/Day). If the Abyss Drider fails a saving throw, it can choose to succeed instead.

Fey Ancestry. The drider has advantage on saving throws against being charmed, and magic can't put the drider to sleep.

Innate Spellcasting. The drider's innate spellcasting ability is Wisdom (spell save DC 16). The drider can innately cast the following spells, requiring no material components:

At will: dancing lights

1/day each: darkness, faerie fire

Spider Climb. The drider can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.

Web Walker. The drider ignores movement restrictions caused by webbing.

Multiattack. The drider makes three attacks, either with its longsword or its longbow. It can replace one of those attacks with a bite attack.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 2 (1d4) piercing damage plus 9 (2d8) necrotic damage.

Bonesword. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d8 + 3) slashing damage, or 8 (1d10 + 3) slashing damage if used with two hands.

Bone Marrow. Ranged Weapon Attack: +8 to hit, range 150/600 ft., one target. Hit: 12 (2d10 + 3) piercing damage plus 4 (1d8) necrotic damage. On a critical hit the arrow pins the creature in place and the creature must make a strength check (DC 15) to remove it.

The Abyss Drider can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. The abyss drider regains spent legendary actions at the start of its turn.

Improvised Earthquake: The Abyss Drider slams the ground with its Bonesword. Everyone within 60 ft. must make a DC17 Dex saving throw or be knocked prone.

Predator's Camouflage: The Abyss Drider can magically change the colour of its bones to hide from its enemies. Make a stealth check to hide in plain sight.

Tactical Jump (Costs 2 Actions): Triple the Abyss Drider's total jump distance until the start of their next turn and use this action to move or dash it's full movement to an unoccupied space.